The prior art has disclosed turbines of the type described above. In a gas turbine (Brayton cycle), a gas is compressed in a compressor, heated in a combustion chamber (with the result that the volume of the gas increases) and then expanded in a turbine. The increased volume of gas during expansion results in more expansion work being supplied than the compression work demanded, which results in a net gain in power. In a steam turbine cycle (Rankine cycle), a liquid is pressurized using a pump, evaporated in a boiler and then expanded in a turbine. The difference between compression work and expansion work means that in this case too there is a net power gain, but the phase difference (liquid/gaseous) means that the difference between compression and expansion work is much greater than in a gas turbine cycle.
In both cases, work is delivered in a rotating turbo machine as a result of kinetic energy (motion energy) and potential energy (pressure) of gases being converted into mechanical energy. This principle can be described using an integral angular momentum balance.
The gas (or vapor) exerts forces, which are associated with the local pressure and any changing velocity of the flow medium, on the walls of flow passages (the blades) of the rotating rotor.
In general, at least three loss mechanisms arise during compression and expansion:    1. Leakage of gas (or vapor) through gaps between the moving rotor surfaces and the stationary casing.    2. Impact losses at the transition in the flow from one flow passage to another flow passage.    3. Frictional losses (at passage and rotor walls and internally in the flowing medium).
Leakage losses are associated with gap widths. In view of the finite absolute dimensional accuracy with which moving seals can be designed (also in view of thermal expansion), sealing problems are significant in particular in the case of small overall dimensions of the compressor and turbine rotor.
In addition, collision losses are proportional to the thickness of the partitions between the flow passages (the blade thickness), which likewise become relatively great if the rotor is of a small overall size.
Finally, velocities and the wall surface area increase in relation to the through-flow surface areas in the case of small dimensions.
WO 00/39440 describes a reaction turbine comprising an inlet located in the vicinity of the center axis of the rotation, this inlet actually being divided into a number of inlet passages connected to a number of individual combustion spaces, and outlet passages which extend to the circumference.
WO 90/01625 discloses a rotating combustion chamber, a boundary of which is formed by a water jacket which forms the circumferential boundary through centrifugal effects.
DE 441730 has disclosed a device without compressor.